1. Technical Field
The present disclosure relates to an auxiliary apparatus for minimally invasive surgery, and, more particularly, for the use of enlarging the visual field.
2. Description of Related Art
Minimally invasive surgery (MIS) utilizes medical scopes, such as gastroscope, enteroscopy, laparoscopy, thoracoscope and relative tools to perform a surgery. The concept of minimal invasion derives from the development of the whole medical pattern and the idea of entire treatment. MIS focuses on the progress and recovery of patients' psychology, sociality, physical pain, spirit and life quality. It takes care of patients and reduces their suffering. During an MIS procedure, surgery targets are accessed through natural orifices or from one to three small incisions 0.5 cm to 1 cm in length, rather than through a large incision in an open surgery approach. The advantages of MIS over conventional surgeries include minimal scar, decreased pain, less hospital time and quick recovery. Therefore, MIS reduces damages and brings convenience to patients.
Endoscopic Submucosal Dissection (ESD), a type of MIS, is applied in early carcinoma or pre-carcinoma abnormalities. More particularly, ESD adapts to patients with mucosal or submucosal invasion and without regional lymph node or distant metastasis. In clinic, ESD is usually used in the following diseases in a digestive tract: (1) polyps and pre-carcinoma abnormalities, especially with surgery targets >2 cm in diameter, in which ESD can completely remove abnormal tissues; (2) early cancer, especially limited to mucosa without lymph node metastasis, may be cured by ESD coupled with chromo endoscopy and ultrasonic endoscopy, which can be as effective as conventional surgery; (3) submucosal cancer, such as leiomyoma, stromal tumor, lipoma and tumors originated from mucosa and submucosa, in which ESD can dissect abnormal tissues. In Japan, almost over half of early stomach cancers and colon cancers are treated with ESD at present.
ESD expands indications for the resections with endoscopy. Early cancer and pre-cancer abnormality in the gastrointestinal tract can be treated effectively due to the thorough removal of abnormal tissues by ESD. Compared with conventional surgery, ESD has less trauma and is more endurable for patients. It is possible to design a personal strategy according to the site, size, shape and features of the abnormal tissues so as to retain normal tissues and functions while a tumor is completely removed. However, during the operation of ESD, the visualization of the surgical field is narrowed because the surgery target on the resected mucosa moves down for gravity, which affects the performance of ESD.